The nock is the part of the arrow which is notched to receive therein the bowstring. The nock is usually positioned on the end of the shaft of an arrow, whereby upon placing the arrow on the bowstring, the nock, with its lateral projections (nock-wings), grips the bowstring. In order to properly establish and mark the portion of the bowstring which should be received within the nock of the arrow, a pair of bands (a nock-location collar) are attached to the bowstring between which is the portion of the bowstring to be received within the nock. It is important that the collar be received and retained in the knock during spanning and firing of the arrow.
Unfortunately, when firing, the bowperson grips the bowstring either with: (1) his/her index finger above the nock-location collar and the middle and remaining fingers below said section; or (2) using the so-called "lower grip", said bowperson grips the bowstring below said collar. In either case, the point of maximum extension of the bowstring, during the spanning of the bow, is below the nock-location collar. Thus, prior to firing the bowstring is tilted upwardly at an angle of up to 30.degree. in the region of the nock-location collar with respect to the bottom of the furrow of the nock (which is formed by the projections or nock-wings) which is perpendicular to the axis of the arrow. This tilting creates problems in that it tends to keep the collar from being properly retained in the nock. Upon firing, the arrow leaves the bowstring when the latter is released from its tensed state by the bowperson and has reached its normal relaxed state. In its normal relaxed state, the bowstring runs parallel to the bottom of the furrow of the nock. This creates problems by requiring that the bottom of the furrow run parallel to the bowstring in its relaxed state.
The two bands defining the nock-location collar on the bowstring have, as a rule, a separation therebetween corresponding to the diameter of the nock, in order to define the section of the bowstring where the nock may be located as accurately as possible. The tilting of the pulled bowstring has the result that the upper band pushes down upon the nock in front of the furrow, whereas the lower band pushes against the bottom of the projections from behind the furrow. Consequently, a tilt moment is applied to the entire arrow which pushes against the alignment of the arrow shaft on the bow. This tilt moment impairs the accuracy of the shot. Under certain conditions, the pressure exerted through the bands upon the nock can even lead to the breaking off of the nock from the arrow shaft.
Nocks of the prior art have been disclosed which have attempted to solve the problems enumerated above by having a furrow formed between the nock projections (nock-wings) in which, at least at its bottom, has a width which is a bit smaller than the diameter of the bowstring. The nock thereby sits upon the bowstring slightly pinched. This is disadvantageous in that when the bow is pulled, the bowstring tilts against the bottom of the furrow of the nock and lifts itself from the bottom of the furrow. With the bow pulled, the collar no longer sits accurately within the nock. Additionally, if the bowstring is released by the bowperson during the discharge of the arrow, then the bowstring strikes against the bottom of the furrow in an irregular manner, resulting in inconsistencies in the discharge of the arrow and in the arrow deviating from its intended flight.
In the West German Utility Model Registration No. DE-GM No. 83 05 301 there is disclosed a nock of the general type mentioned previously. In this nock, ribs are formed on the inner sides of the projections extending to the rear of the bottom of the furrow, which are transverse to the axis of the arrow and are parallel to the bottom of the furrow. These ribs narrow the furrow to such an extent, so that the bowstring, when received in the nock, is seated on the bottom of the furrow, in front of the ribs, being held in the nock with a slight holding force. This holding action holds the nock fast upon the bowstring. If the bowstring is tilted during the spanning of the bow, then it tilts against the canal defined between the bottom of the furrow and the ribs. This disadvantageously creates the danger that the bowstring may jump out of the seat or become otherwise unseated. The arrow then sits with the nock-location collar of the bowstring being no longer received within the nock and can even fall off from the bowstring. In addition, with the nock disclosed in West German Utility Model Registration No. DE-GM No. 83 05 301, the bottom of the furrow is arched in a convex fashion with respect to its peripheral ends, in order to guarantee the accurate alignment of the nock-location collar of the bowstring with the bottom of the furrow of the nock, even during the tilting of the pulled bowstring. This convex arching of the bottom of the furrow, however, has the result that the bowstring at any one time is only in point contact with the bottom of the furrow. Because of this point contact, the arrow, particularly at the moment during the discharge-firing-thereof when it leaves the bowstring, is not accurately directed by the nock-location collar of the bowstring.
Accordingly, there remains a need to create a nock which, when the bowstring is extended during the spanning of the bow and the discharge of the arrow, will be held dependably against the nock-location collar of the bowstring and which at all times permits the nock-location collar of the bowstring to lie evenly against the bottom of the furrow of the nock, for the accurate direction of the arrow.